package com.wangjiawei.mvc;

import javax.servlet.ServletConfig;
import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;
import java.io.InputStream;
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;
import java.util.Properties;

/**
 * 2 * @Author: 小王同学
 * 3 * @Date: 2020/9/29 21:22
 * 4
 */
public class DispatcherServlet extends HttpServlet {

    @Override
    public void init(ServletConfig config) throws ServletException {
        String path = config.getInitParameter("contentConfigLocation");
        InputStream is = DispatcherServlet.class.getClassLoader().getResourceAsStream(path);
        HandlerMapping.load(is);
    }

    @Override
    protected void service(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        // 获取用户请求的uri
        String uri = req.getRequestURI();
        HandlerMapping.MVCMapping mvcMapping = HandlerMapping.get(uri);

        if (mvcMapping == null){
            resp.sendError(404, "MVC：映射地址不存在" + uri);
            return;
        }

        Object obj = mvcMapping.getObj();
        Method method = mvcMapping.getMethod();
        Object result = null;
        try {
            result = method.invoke(obj, req, resp);
        } catch (IllegalAccessException e) {
            e.printStackTrace();
        } catch (InvocationTargetException e) {
            e.printStackTrace();
        }
        switch (mvcMapping.getType()){
            case TEXT:
                resp.getWriter().write((String) result);
                break;
            case VIEW:
                resp.sendRedirect((String) result);
                break;
            default:
                break;
        }

    }
}
